Dyslipidaemia in nephrotic syndrome: mechanisms and treatment

Causal associations between environmental factors and risk of IgA nephropathy and membranous nephropathy: a bidirectional Mendelian randomization and mediation analysis

AIMS

IgA nephropathy (IgAN) and membranous nephropathy (MN) have intricate etiologies that are poorly understood. This study aimed to investigate the impact of genetically predicted environmental factors on IgAN and MN.

METHODS

We used bidirectional two-step Mendelian randomization (MR) analysis utilizing large-scale genome-wide association study (GWAS) data to investigate the relationships between 68 environmental exposures and IgAN and MN. The main method is inverse variance weighted (IVW). Sensitivity analyses were conducted to validate the causal estimates. Furthermore, the two-step MR was used to explore possible mediating effects.

RESULTS

A total of 20 significant causal associations were identified. Genetically predicted educational attainment (EA), average household income, gluten-free diet, cheese intake, fresh fruit intake, cognitive performance, and intelligence were associated with a reduced risk of IgAN (p < 0.05); whereas frequency of alcohol consumption, insomnia, triglycerides, transferrin saturation, percentage body fat, body mass index (BMI), waist circumference, and blood pressure were associated with the risk of IgAN (p < 0.05). Genetically predicted EA and moderate to vigorous physical activity were associated with a reduced risk of MN (p < 0.05); on the other hand, beef intake, waist-to-hip ratio, and nitrogen oxides were associated with the risk of MN (p < 0.05). In addition, we observed that insomnia, BMI, and waist circumference partially mediated the causal link between EA and IgAN, with mediation proportions of 12.52%, 11.06%, and 9.93%, respectively.

CONCLUSIONS

This study provides novel evidence of causal relationships between 20 genetically predicted environmental factors and the risk of IgAN and MN. These findings may inform targeted prevention strategies and contribute to improved disease risk assessment.

Causal association of circulating immune cells with nephrotic syndrome: evidence from a two-sample Mendelian randomization study

OBJECTIVE

Nephrotic syndrome, a debilitating manifestation of kidney disease, often arises from diverse glomerular disorders and is accompanied by notable comorbidities. Despite indications of an immunological etiology, the precise role of immune cells in its pathogenesis remains unclear. This study aimed to elucidate the causal relationships between circulating immune cell phenotypes and nephrotic syndrome using a rigorous bidirectional Mendelian randomization approach.

METHODS

We conducted a bidirectional Mendelian randomization analysis leveraging public genome-wide association studies (GWAS) datasets to investigate the causal links between 731 immune cell features and nephrotic syndrome. Our primary analysis employed inverse variance weighting (IVW), complemented by MR-Egger regression, simple model, weighted median method, and weighted model techniques to ensure robustness. Sensitivity analyses were performed to address potential biases arising from heterogeneity, horizontal pleiotropy, and single-nucleotide polymorphism (SNP) instability in nephrotic syndrome.

RESULTS

Among traits examined, 13 immune cell phenotypes were identified to have significant causal impacts on nephrotic syndrome (adjusted P >  < 0.05). Among these phenotypes, CD25 on unswitched memory B cell, CD25 on memory B cell, CD25 on CD24 + CD27 + B cell, CD25 on IgD-CD38-B cell, CD33dim HLA DR-Absolute Count, and CD127 on granulocyte emerged as causal risk factors, while seven circulating immune cell phenotypes, predominantly monocyte subsets, exhibited protective effects. Furthermore, the reverse Mendelian randomization analysis demonstrated significant effects of nephrotic syndrome on 27 immune phenotypes (P < 0.05).

CONCLUSION

The genetic predictions indicate that multiple circulating immune cell phenotypes, particularly CD25 on specific B-cell subsets, serve as independent risk factors for the onset and progression of nephrotic syndrome. Conversely, monocytes expressing specific phenotypes may exert protective effects against the development of nephrotic syndrome. These findings offer a novel therapeutic approach for the prevention and treatment of nephrotic syndrome.

Emerging roles of PCSK9 in kidney disease: lipid metabolism, megalin regulation and proteinuria

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD). Key features of CKD include proteinuria and reduced glomerular filtration rate, both of which are linked to disease progression and adverse outcomes. Dyslipidemia, a major CVD risk factor, often correlates with CKD severity and is inadequately addressed by conventional therapies. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a critical role in lipid metabolism by modulating low-density lipoprotein receptor (LDLR) levels and has emerged as a therapeutic target for managing dyslipidemia. PCSK9 inhibitors, including monoclonal antibodies and siRNA, effectively lower LDL cholesterol levels and have demonstrated safety in patients with mild to moderate CKD. Recent findings indicate that PCSK9 aggravates proteinuria by interacting with and downregulating megalin, a proximal tubule receptor essential for protein reabsorption in the kidney. Inhibition of PCSK9 has been shown to preserve megalin levels, reduce proteinuria, and improve the disease phenotype in experimental models. However, conflicting data from preclinical studies underscore the need for further research to clarify the mechanisms underlying PCSK9's role in kidney disease. This review highlights the potential of PCSK9 inhibition in addressing proteinuria and dyslipidemia in CKD, emphasizing its promise as a therapeutic strategy, while addressing current challenges and future directions for research.

Nutritional management of pediatric nephrotic syndrome regarding oxidative stress and antioxidant balance

Pediatric nephrotic syndrome remains a complex clinical entity, with incompletely elucidated pathogenetic mechanisms, in which oxidative stress appears to have a substantial etiopathogenic role. Recent evidence supports the involvement of redox imbalance in podocyte damage, impaired glomerular function, and systemic decline. All this suggests that antioxidant interventions can favorably modulate the course of the disease. This narrative review aims to synthesize the most relevant data from the current literature on the interaction between oxidative stress and nephrotic syndrome in children, with a focus on the therapeutic potential of antioxidants. The analysis focuses on the molecular mechanisms by which oxidative stress contributes to the progression of renal dysfunction, the role of oxidative biomarkers in disease monitoring, and the ability of antioxidants to reduce the need for immunosuppressants and corticosteroids, thus contributing to the decrease in associated morbidity. The translational perspectives of antioxidant therapy are also discussed, in the context of the urgent need for effective adjuvant strategies with a safety profile superior to conventional therapies. By integrating these data, the paper supports the valorization of antioxidant interventions as an emerging direction in the management of pediatric nephrotic syndrome and substantiates the need for controlled clinical trials, with rigorous design, in this field.

Risk factors and predictive model for renal outcomes in autoimmune membranous nephropathy with and without acute kidney injury: a retrospective cohort study

Objective

This study aimed to delineate the risk factors affecting renal outcomes in autoimmune membranous nephropathy (aMN) with or without acute kidney injury (AKI) and develop a predictive model.

Methods

This retrospective cohort study included 441 patients with biopsy-confirmed aMN from the First Affiliated Hospital of Fujian Medical University (January 2010 to March 2023). Patients were grouped based on the presence of AKI and followed up until a renal endpoint event (progression to end-stage renal disease, initiation of dialysis, or either a >40% decline in estimated glomerular filtration rate from baseline or a doubling of serum creatinine levels from baseline, both sustained for ≥3 months) or study endpoint (March 2024). Clinicopathological and renal outcomes were collected and analyzed. Risk factors for renal endpoints were identified via Cox regression analyses, and a nomogram was constructed. Model performance was evaluated using the C-index, time-dependent receiver operating characteristic (Time-ROC) curves, calibration curves, and decision curve analysis (DCA). Kaplan-Meier survival curves compared renal survival between AKI subgroups.

Results

Among 441 patients, 109 (24.72%) experienced AKI. Renal endpoint events occurred in 40.4% of the AKI group and 4.5% of the non-AKI group. Multivariate Cox regression identified AKI (HR = 7.298, P < 0.001), triglycerides (HR = 1.140, P = 0.002), serum creatinine (HR = 1.008, P = 0.012), hematuria (HR = 2.246, P = 0.040), and kidney anti-M-type phospholipase A2 receptor staining 4+ (HR = 2.473, P = 0.003) as independent risk factors, while serum C3 (HR = 0.082, P < 0.001) was an independent protective factor. The nomogram had a C-index of 0.845 (P < 0.001), with Time-ROC AUCs of 0.92, 0.81, 0.83, and 0.87 for 3 to 6 years, respectively. Calibration plots revealed good consistency between the predicted and actual probabilities. DCA indicated that the nomogram had potential clinical utility. Kaplan-Meier analysis showed lower cumulative renal survival in patients with AKI (P < 0.001).

Conclusions

The risk factor model suggests that renal outcomes in patients with aMN can be predicted. Early assessment and management targeting these identified risk factors could help delay renal function decline in these patients.

Salivary Interleukin-6 and Interleukin-18 Levels and Their Association with Dental Health in Children with Idiopathic Nephrotic Syndrome

Idiopathic nephrotic syndrome (NS) is associated with immune dysfunction and increased susceptibility to infections. Oral health may influence systemic inflammation and disease progression. This study aimed to evaluate the salivary levels of interleukin-6 (IL-6) and interleukin-18 (IL-18) in children with NS and their association with dental health, particularly caries prevalence and the consequences of untreated caries. A cross-sectional study was conducted on 86 children aged 5-17 years, including 40 NS patients and 46 healthy controls. Clinical dental examinations assessed caries prevalence using the dmft/DMFT index and the impact of untreated caries using the pufa/PUFA index. Unstimulated saliva samples were collected, and IL-6 and IL-18 concentrations were measured using enzyme-linked immunosorbent assay. NS patients exhibited a significantly lower prevalence of active carious lesions than controls (50% vs. 72%, p = 0.039). The DMFT index was lower in the NS group (p = 0.003). Salivary IL-6 levels were significantly reduced in NS patients compared to controls (p = 0.015), while IL-18 levels showed no significant difference. IL-6 positively correlated with decayed permanent teeth and pulp/periapical tissue diseases, whereas IL-18 correlated with white spot lesions and pulp infections. IL-6 and IL-18 could serve as potential non-invasive indicators of disease progression in NS patients.

The Non-High-Density Lipoprotein Cholesterol (Non-HDL-C) to HDL-C Ratio (NHHR) and Its Association with Chronic Kidney Disease in Chinese Adults with Type 2 Diabetes: A Preliminary Study

Objectives: The objective of this study was to examine the association between non-high-density lipoprotein cholesterol (non-HDL-C) to high-density lipoprotein cholesterol (HDL-C) ratio (NHHR) and chronic kidney disease (CKD) in Chinese adults with type 2 diabetes mellitus (T2DM). Methods: This study originated from a survey carried out in Zhejiang Province, located in eastern China, between March and November 2018. To explore the relationship between NHHR and CKD, a multivariable logistic regression model was employed. The dose-response relationship was assessed using restricted cubic spline (RCS) analysis, while generalized additive models (GAMs) were applied to examine the associations between NHHR and urinary albumin-to-creatinine ratio (UACR) as well as estimated glomerular filtration rate (eGFR). Subgroup analyses were performed across various demographic and clinical categories to assess the consistency of the NHHR-CKD association. The optimal NHHR cutoff for CKD diagnosis, its predictive accuracy, and its comparison with its components and HbA1c were determined through receiver operating characteristic (ROC) curve analysis. Results: The study enrolled 1756 participants, including 485 individuals with CKD and 1271 without CKD. Multivariable logistic regression revealed a significant positive association between NHHR and CKD, with each standard deviation (SD) increase in NHHR linked to a 23% higher odds of CKD (OR = 1.23, 95% CI: 1.09-1.37) after adjusting for potential confounders. When comparing quartiles, the fully adjusted ORs for Q2, Q3, and Q4 were 1.29 (0.92-1.79), 1.31 (0.94-1.83), and 1.87 (1.34-2.60), respectively, relative to Q1 (p for trend < 0.01). RCS analysis confirmed a linear dose-response relationship between NHHR and CKD in both sexes (p for nonlinearity > 0.05). GAMs indicated a significant positive correlation between NHHR and UACR (ρ = 0.109, p < 0.001) but no significant association with eGFR (ρ = -0.016, p = 0.502). Subgroup analyses demonstrated consistent associations across most subgroups, except for the 18-44 years age group, the well-controlled glycemic group, and the non-alcohol drinking group (p > 0.05). ROC curve analysis identified an optimal NHHR cutoff of 3.48 for CKD prediction, with an area under the curve (AUC) of 0.606 (95% CI: 0.577-0.635). Notably, NHHR outperformed its individual components and HbA1c in predictive performance. Conclusions: This study revealed a linear link between higher NHHR levels and increased CKD prevalence in Chinese T2DM patients. NHHR may also serve as a potential complementary biomarker for early CKD detection, though further prospective studies are needed to confirm its predictive value and clinical utility in high-risk T2DM populations.

Proatherogenic changes in the quantity and quality of lipoproteins in adults with idiopathic nephrotic syndrome

OBJECTIVE

Lipoprotein subclasses and high-density lipoprotein (HDL) functions are associated with atherosclerotic cardiovascular disease (ASCVD), but researches on them in patients with nephrotic syndrome (NS) are limited. The aims of this study were (1) to analyze the changes in quantity and quality of lipoprotein in patients with idiopathic nephrotic syndrome (INS) and patients in remission from NS, and (2) to evaluate the lipid-related atherosclerotic risk in these patients.

METHODS

51 patients with idiopathic nephrotic syndrome (NS group), 72 NS patients with complete remission (NS remission group), and 80 healthy controls (control group) were recruited. The levels of conventional lipids, lipoprotein subclasses, including VLDL, IDL (C, B, A), LDL (LDL1-7), HDL (large, intermediate, small) and HDL cholesterol efflux capacity (CEC), were measured and compared across the three groups.

RESULTS

Conventional lipid parameters [TG, TC, LDL-C, apo-B and Lp(a)] and lipoprotein subclasses (VLDL, IDL-C, IDL-B, LDL-2 and sdLDL) were higher in NS group when compared to NS remission group and control group (P < 0.05). CEC in NS group was significantly lower than that in control group [21.0 (18.3-27.2) % vs 25.7 (23.3-28.9) %] (P < 0.001) and improved to 22.8 (20.6-23.7) % in NS remission group with the disease recovery.

CONCLUSION

Proatherogenic changes in conventional lipid parameters, lipoprotein subclasses and HDL-CEC were observed in patients with NS, suggesting that more rigorous lipid regulation strategies may help reduce cardiovascular disease risk in patients with NS.

ECHS1 as a Lipid Metabolism Biomarker for Pediatric Focal Segmental Glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome and often leads to end-stage renal disease. However, the underlying pathophysiological mechanisms that contribute to disease progression require further investigation to establish appropriate therapeutic targets and biomarkers. This study aimed to clarify the molecular mechanisms underlying FSGS by focusing on differentially expressed genes (DEGs) and lipid metabolism-related genes (LMRGs). We utilized the GSE69814, GSE129973, and GSE121233 datasets, which comprise glomerular transcriptomes from patients with FSGS, minimal change disease (MCD), and unaffected kidney tissues. We identified 2,459 DEGs from the GSE69814 dataset and 982 DEGs from the GSE129973 dataset. These DEGs intersected 1,450 LMRGs, resulting in 56 differentially expressed LMRGs (DELMRGs). Enrichment analysis revealed that these DELMRGs were primarily involved in fatty acid metabolic processes; localized in microbodies, peroxisomes, and mitochondrial matrices; and exhibited oxidoreductase activity. Protein-protein interaction networks were constructed using Cytoscape, and five hub DELMRGs (enoyl-CoA hydratase, short chain 1 [ECHS1], EHHADH, IDH1, SUCLG1, and ALDH3A2) were identified using multiple algorithms. We assessed the diagnostic performance using receiver operating characteristic curves and expression levels from the GSE121233 dataset, and found that ECHS1 and ALDH3A2 showed strong diagnostic potential. Immunohistochemical verification of clinical specimens from children confirmed significant expression of ECHS1 in FSGS compared with that in normal and MCD tissues. This study highlights ECHS1 as a potential biomarker for pediatric FSGS, suggesting a potential role in early diagnosis or personalized treatment, offering insights into its pathogenesis and paving the way for targeted therapeutic strategies.

TSH-stimulated hepatocyte exosomes modulate liver-adipose triglyceride accumulation via the TGF-β1/ATGL axis in mice

Subclinical hypothyroidism (SCH) contributes to obesity, with the liver acting as a crucial metabolic regulator. Thyroid-stimulating hormone (TSH) affects systemic lipid balance, potentially linking SCH to obesity. While the direct impact of TSH on hepatic lipid metabolism has been extensively documented, its role in modulating lipid dynamics in peripheral organs through liver-mediated pathways remains insufficiently understood. This study identifies TSH-stimulated hepatocyte-derived exosomes (exosomesTSH) as key mediators in liver-adipose communication, promoting triglyceride accumulation in adipocytes via the transforming growth factor-beta 1 (TGF-β1)/adipose triglyceride lipase (ATGL) axis. ExosomesTSH enhance lipid storage in adipocytes, significantly increasing triglyceride content and lipid droplet formation while reducing lipolysis, effects that are dependent on TSH receptor (TSHR) activation in hepatocytes. In vivo, exosomesTSH induce weight gain and adipose tissue expansion, impairing glucose metabolism in both chow- and high-fat diet-fed mice. Mechanistically, exosomesTSH upregulate TGF-β1 and downregulate ATGL in adipocytes, establishing the TGF-β1/ATGL pathway as essential for exosome-mediated lipid accumulation. Further, miR-139-5p is identified as a modulator of TGF-β1 expression within this pathway, with overexpression of miR-139-5p alleviating exosomesTSH-induced lipid accumulation in adipocytes. This study elucidates a novel miR-139-5p-dependent mechanism through which TSH modulates lipid metabolism via liver-derived exosomes, highlighting the pivotal role of miR-139-5p in linking SCH to adipose lipid accumulation through the TGF-β1/ATGL signaling axis.

Renal Lipidosis in Horses and Donkeys: 25 Cases (2008-2022)

BACKGROUND

Renal lipidosis is a well-documented histologic finding in humans and small animals with renal and metabolic disorders, but it is not well described in equids.

OBJECTIVE

To describe the signalment, clinicopathologic indices, and postmortem findings of equids with a histologic diagnosis of both hepatic and renal lipidosis (HL + RL) and compare them to cases with hepatic lipidosis only (HL).

ANIMALS

Equids with necropsy findings of renal or hepatic lipidosis (state diagnostic lab) between 2008 and 2022.

METHODS

Retrospective case-control study. Signalment, history, necropsy diagnosis, and selected biochemical data at admission were extracted from medical records. Each case of HL + RL was assigned a matched case from group HL for comparison of clinical data.

RESULTS

Renal lipidosis was diagnosed in 0.5% (25/4680) of equid necropsies. Donkeys (7/13) and pony/miniature horses (13/37) with hepatic lipidosis were more likely to also have renal lipidosis compared to horses (5/141; p = 0.0006, RR = 15.1and p < 0.0001, RR = 9.9, respectively). No cases of renal lipidosis were identified without concurrent hepatic lipidosis. The predominant presenting complaints involved gastrointestinal (16/25) and neurologic (12/25) systems. Compared to group HL, group HL + RL had significantly higher admission plasma lactate concentration (+6.2 mmol/L, 95% CI 0.04-13.1, p = 0.04) and GGT activity (+246 U/L, 95% CI -480.4-1870, p = 0.02). No significant differences were detected in creatinine or triglyceride concentrations.

CONCLUSIONS

Renal lipidosis is an occasional postmortem finding in equids with hepatic lipidosis and is more common in donkeys, ponies, and miniature horses compared to horses. The clinical implications of renal lipidosis remain unclear.

High-Density Lipoprotein in Patients with Diabetic Kidney Disease: Friend or Foe?

High-density lipoprotein (HDL) exhibits multiple metabolic protective functions, such as facilitating cellular cholesterol efflux, antioxidant, anti-inflammatory, anti-apoptotic and anti-thrombotic properties, showing antidiabetic and renoprotective potential. Diabetic kidney disease (DKD) is considered to be associated with high-density lipoprotein cholesterol (HDL-C). The hyperglycemic environment, non-enzymatic glycosylation, carbamylation, oxidative stress and systemic inflammation can cause changes in the quantity and quality of HDL, resulting in reduced HDL levels and abnormal function. Dysfunctional HDL can also have a negative impact on pancreatic β cells and kidney cells, leading to the progression of DKD. Based on these findings, new HDL-related DKD risk predictors have gradually been proposed. Interventions aiming to improve HDL levels and function, such as infusion of recombinant HDL (rHDL) or lipid-poor apolipoprotein A-I (apoA-I), can significantly improve glycemic control and also show renal protective effects. However, recent studies have revealed a U-shaped relationship between HDL-C levels and DKD, and the loss of protective properties of high levels of HDL may be related to changes in composition and the deposition of dysfunctional particles that exacerbate damage. Further research is needed to fully elucidate the complex role of HDL in DKD. Given the important role of HDL in metabolic health, developing HDL-based therapies that augment HDL function, rather than simply increasing its level, is a critical step in managing the development and progression of DKD.

Kidney fat by magnetic resonance spectroscopy in type 2 diabetes with chronic kidney disease

BACKGROUND AND HYPOTHESIS

The kidneys may be susceptible to ectopic fat and its lipotoxic effects, disposing them to chronic kidney disease (CKD) in type 2 diabetes (T2D). We investigated whether the kidney parenchyma fat content and kidney sinus fat volume would be higher in persons with T2D and CKD.

METHODS

Cross-sectional study including 29 controls, 27 persons with T2D and no CKD, and 48 persons with T2D and early CKD (urine albumin creatinine ratio (UACR) ≥ 30 mg/g). Kidney parenchyma fat content and kidney sinus fat volume were assessed using magnetic resonance spectroscopy and Dixon scans respectively.

RESULTS

In the control, T2D without CKD and T2D with CKD groups, respectively, median [1st - 3rd quartile] UACR was 5 [4 - 6], 6 [5 - 10] and 95 [43 - 278] mg/g. and mean ± standard deviation estimated glomerular filtration rate was 89 ± 11, 94 ± 11 and 77 ± 22 ml/min/1.73m2. Kidney parenchyma fat content was, respectively, 1.0 [0.5-2.4], 0.7 [0.2-1.2], 1.0 [0.3-2.0] % (p = 0.26). Kidney sinus fat volume was 2.8 [1.6-7.6], 8.0 [4.7-11.3], 10.3 [5.7-14.0] ml (p < 0.01). Around 90 % of T2D participants received a sodium-glucose cotransporter-2 inhibitor or glucagon-like peptide-1 receptor agonist.

CONCLUSIONS

In a setting of modern, multifactorial T2D management, kidney parenchyma fat content, evaluated with magnetic resonance spectroscopy, was similar among healthy controls and persons with T2D irrespective of CKD status. Still, kidney sinus fat volume was higher in the presence of T2D and higher still with CKD.

Membranous Nephropathy

Membranous nephropathy is a glomerular disease that may be caused by exogenous risk factors in genetically predisposed individuals (primary MN) or may be associated with other autoimmune diseases, drug exposure, or cytotoxic agents (secondary MN). Primary membranous nephropathy (PMN) is an autoimmune disease in which antigens-mainly the phospholipase A2 receptor-are located in the podocytes and are targeted by circulating antibodies, leading to in situ formation of immune complexes that activate the complement system. Clinically, the disease is characterized by nephrotic syndrome (NS) and associated complications. The outcome of PMN can vary, but untreated patients with NS may progress to end-stage kidney disease (ESKD) in 35-40% of cases within 10 years. Treatment primarily aims to prevent NS complications and progression to ESKD. The most commonly used immunosuppressive drugs are rituximab, corticosteroids, cyclophosphamide, and calcineurin inhibitors. Most patients may experience an improvement of proteinuria, which can sometimes be followed by NS relapse. Fewer than 50% of patients with PMN achieve complete and stable remission. In addition to immunosuppressive therapy, antiproteinuric, anti-lipemic, and anticoagulant medicaments are often required.

Genetic association analysis of lipid-lowering drug target genes in chronic kidney disease

Objective

The impact of lipid-lowering medications on chronic kidney disease (CKD) remains a subject of debate. This Mendelian randomization (MR) study aims to elucidate the potential effects of lipid-lowering drug targets on CKD development.

Methods

We extracted 11 genetic variants encoding targets of lipid-lowering drugs from published genome-wide association study (GWAS) summary statistics, encompassing LDLR, HMGCR, PCSK9, NPC1L1, APOB, ABCG5/ABCG8, LPL, APOC3, ANGPTL3, and PPARA. A Mendelian randomization analysis was conducted targeting these drug-related genes. CKD risk was designated as the primary outcome, while estimated glomerular filtration rate (eGFR) and blood urea nitrogen (BUN) were assessed as secondary outcomes. Additionally, mediation analysis was performed utilizing 731 immune cell phenotypes to identify potential mediators.

Results

The meta-analysis revealed a significant association between ANGPTL3 inhibitors and a reduced risk of CKD (OR [95% CI] = 0.85 [0.75-0.96]). Conversely, LDLR agonists were significantly linked to an increased risk of CKD (OR [95% CI] = 1.11 [1.02-1.22]). Regarding secondary outcomes, lipid-lowering drugs did not significantly affect eGFR and BUN levels. Mediation analysis indicated that the reduction in CKD risk by ANGPTL3 inhibitors was mediated through modulation of the immune cell phenotype, specifically HLA-DR on CD14+ CD16+ monocytes (Mediated proportion: 4.69%; Mediated effect: -0.00899).

Conclusion

Through drug-targeted MR analysis, we identified a causal relationship between lipid-lowering drug targets and CKD. ANGPTL3 and LDLR may represent promising candidate drug targets for CKD treatment.

Lipid metabolism disorders and albuminuria risk: insights from National Health and Nutrition Examination Survey 2001-2018 and Mendelian randomization analyses

BACKGROUND

Previous studies have revealed an underlying connection between abnormal lipid metabolism and albuminuria. We aim to investigate the causal relationship between lipid metabolism disorders and the risk of albuminuria from both a population and genetic perspective.

METHODS

A cross-sectional study was conducted by using data from the National Health and Nutrition Examination Survey (NHANES) 2001-2018. Multivariable-adjusted logistic regression, subgroup analysis, interaction tests and restricted cubic spline (RCS) were employed statistically. Mendelian randomization (MR) analysis was performed to validate the causal relationship between exposure and outcome to mitigate confounding factors and reverse causation interference.

RESULTS

After adjusting for confounders, HDL levels (1.03-2.07 nmol/L) were associated with a reduced risk of albuminuria. In contrast, elevated cholesterol levels (>6.2 nmol/L) and triglyceride levels (>2.3 nmol/L) were associated with an increased risk of albuminuria. Serum triglyceride concentration emerged as a potential risk factor for albuminuria. In MR analysis, a reduced risk of albuminuria was associated with serum total HDL level (IVW: OR = 0.91, 95% CI = 0.86-0.97, p = 0.002). In contrast, cholesterol esters in medium VLDL (IVW: OR = 1.05, 95% CI = 1.00-1.10, p = 0.032), chylomicrons and extremely large VLDL (IVW: OR = 1.08, 95% CI = 1.03-1.14, p = 0.003), and triglycerides (IVW: OR = 1.14, 95% CI = 1.09-1.19, p < 0.001) were associated with an increased risk of albuminuria.

CONCLUSION

A causal relationship exists between serum lipid metabolism disorder and albuminuria risk. Further validation of additional blood lipid metabolism biomarkers is imperative for future studies.

Associations between the Serum Triglyceride Level and Kidney Outcome in Patients with Chronic Kidney Disease: The Fukuoka Kidney disease Registry Study

AIMS

Hypertriglyceridemia is a risk factor for chronic kidney disease (CKD). However, whether or not it predicts the risk of CKD progression is unknown. This study evaluated the association between serum triglyceride (TG) levels and kidney disease progression in patients with non-dialysis-dependent CKD.

METHODS

The Fukuoka Kidney disease Registry (FKR) study was a multicenter, prospective longitudinal cohort study. In total, 4,100 patients with CKD were followed up for 5 years. The primary outcome was the incidence of CKD progression, defined as a ≥ 1.5-fold increase in serum creatinine level or the development of end-stage kidney disease. The patients were divided into quartiles according to baseline serum TG levels under non-fasting conditions: Q1 ＜87 mg/dL; Q2, 87-120 mg/dL; Q3, 121-170 mg/dL, and Q4 ＞170 mg/dL.

RESULTS

During the 5-year observation period, 1,410 patients met the criteria for CKD progression. The multivariable-adjusted Cox proportional hazards model showed a significant association between high serum TG level and the risk of CKD progression in the model without macroalbuminuria as a covariate (multivariable hazard ratio[HR] for Q4 versus Q1, 1.20; 95% CI, 1.03-1.41; P=0.022), but the significance disappeared after adjusting for macroalbuminuria (HR for Q4 versus Q1, 1.06; 95% CI, 0.90-1.24; P=0.507).

CONCLUSIONS

The present findings suggest that individuals with high serum TG levels are more likely to develop CKD progression than those without; however, whether or not higher serum TG levels reflect elevated macroalbuminuria or lead to CKD progression via elevated macroalbuminuria is unclear.

Omega-3 supplementation attenuates doxorubicin-induced cardiotoxicity but is not related to the ceramide pathway

Cardiotoxicity is the serious side effect of doxorubicin treatment. Ceramides are formed from the degradation of sphingolipids in cell membranes and play an important role in signaling and modulating biological processes. There is evidence that omega-3 fatty acid administration can act on this pathway. To evaluate the role of the ceramide pathway in the pathophysiology of doxorubicin-induced cardiotoxicity and the effect of omega-3 fatty acid supplementation in the attenuation of chronic doxorubicin-induced cardiotoxicity in rats. Sixty male Wistar rats were divided into four groups: Control (C), Doxorubicin (D), Omega-3 fatty acids (W), and Doxorubicin + Omega-3 fatty acids (DW). The groups received omega-3 fatty acids (400 mg/kg/day, via gavage) or water for 6 weeks and doxorubicin (3.5 mg/kg, intraperitoneal) or saline once a week for 4 weeks. Doxorubicin-treated animals showed increases in left atrium and left ventricle diameters, serum triglycerides and cholesterol, malondialdehyde, and protein carbonylation. We also observed a decrease in left ventricular shortening fraction and nSMase1 expression in the heart. Omega-3 fatty acid supplementation attenuated the structural and functional alterations caused by doxorubicin and decreased protein carbonylation. In contrast to doxorubicin, omega-3 fatty acids increased neutral nSMase activity in animals that both received and did not receive doxorubicin but with no effect on nSMase1 protein expression. Omega-3 fatty acid supplementation attenuated the cardiotoxicity caused by doxorubicin. The ceramide pathway may be involved in the pathophysiology of cardiotoxicity, but it is not the mechanism by which omega-3 fatty acids attenuated cardiac dysfunction.

The Dual Burden: Exploring Cardiovascular Complications in Chronic Kidney Disease

Chronic kidney disease (CKD) represents a significant global health challenge, affecting millions of individuals and leading to substantial morbidity and mortality. This review aims to explore the epidemiology, cardiovascular complications, and management strategies associated with CKD, emphasizing the importance of preventing cardiovascular disease and early intervention. CKD is primarily driven by conditions such as diabetes mellitus, hypertension, and cardiovascular diseases, which often coexist and exacerbate renal impairment. Effective management requires a multifaceted approach, including lifestyle modifications, pharmacological interventions, and regular monitoring. Dietary changes, such as sodium restriction and a controlled intake of phosphorus and potassium, play a vital role in preserving renal function. Pharmacological therapies, particularly angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and emerging agents like SGLT2 inhibitors, have shown efficacy in slowing disease progression and improving patient outcomes. Furthermore, patients undergoing dialysis face increased cardiovascular risk, necessitating comprehensive management strategies to address both renal and cardiac health. As the landscape of CKD treatment evolves, ongoing research into novel therapeutic options and personalized medical approaches are essential. This review underscores the urgent need for awareness, education, and effective preventive measures to mitigate the burden of CKD and enhance the quality of life for affected individuals.

An Updated Comprehensive Review on Diseases Associated with Nephrotic Syndromes

There have been exciting advances in our knowledge of primary glomerular diseases and nephrotic syndromes in recent years. Beyond the histological pattern from renal biopsy, more precise phenotyping of the diseases and the use of modern nephrogenetics helps to improve treatment decisions and sometimes also avoid unnecessary exposure to potentially toxic immunosuppression. New biomarkers have led to easier and more accurate diagnoses and more targeted therapeutic decisions. The treatment landscape is becoming wider with a pipeline of promising new therapeutic agents with more sophisticated approaches. This review focuses on all aspects of entities that are associated with nephrotic syndromes with updated information on recent advances in each field. This includes podocytopathies (focal segmental glomerulosclerosis and minimal-change disease), membranous nephropathy, membranoproliferative glomerulonephritis, IgA nephropathy, fibrillary glomerulonephritis, amyloidosis, and monoclonal gammopathy of renal significance in the context of the nephrotic syndrome, but also renal involvement in systemic diseases, diabetic nephropathy, and drugs that are associated with nephrotic syndromes.

Exploring the therapeutic mechanism of Yuebi decoction on nephrotic syndrome based on network pharmacology and experimental study

OBJECTIVE

This study aimed to explore the material basis of YBD and its possible mechanisms against NS through network pharmacology, molecular docking, and in vivo experiment.

METHODS

Active ingredients and potential targets of YBD were obtained through TCMSP and SwissTargetPrediction. NS-related targets were obtained from GeneCards, PharmGKB, and OMIM databases. The herb-ingredient-target network and PPI network were constructed by Cytoscape 3.9.1 and STRING database. GO and KEGG analyses were performed by DAVID database and ClueGO plugin. The connection between main active ingredients and core targets were revealed by molecular docking. To ascertain the effects and molecular mechanisms of YBD, a rat model was established by PAN.

RESULTS

We collected 124 active ingredients, 269 drug targets, and 2089 disease targets. 119 overlapping were screened for subsequent analysis. PPI showed that AKT1, STAT3, TRPC6, CASP3, JUN, PPP3CA, IL6, PTGS2, VEGFA, and NFATC3 were potential therapeutic targets of YBD against NS. Through GO and KEGG analyses, it showed the therapeutic effect of YBD on NS was closely involved in the regulation of pathways related to podocyte injury, including AGE-RAGE signaling pathway in diabetic complications and MAPK signaling pathway. Five key bioactive ingredients of YBD had the good affinity with the core targets. the experiment confirmed the renoprotective effects of YBD through reducing podocyte injury. Furthermore, YBD could downregulate expressions of PPP3CA, STAT3, NFATC3, TRPC6, and AKT1 in rats.

CONCLUSIONS

YBD might be a potential drug in the treatment of NS, and the underlying mechanism is closely associated with the inhibition of podocyte injury.

2024 KSoLA consensus on secondary dyslipidemia

Elevated blood cholesterol and triglyceride levels induced by secondary causes are frequently observed. The identification and appropriate handling of these causes are essential for secondary dyslipidemia treatment. Major secondary causes of hypercholesterolemia and hypertriglyceridemia include an unhealthy diet, diseases and metabolic conditions affecting lipid levels, and therapeutic side effects. It is imperative to correct secondary causes prior to initiating conventional lipid-lowering therapy. Guideline-based lipid therapy can then be administered based on the subsequent lipid levels.

2024 KSoLA Consensus on Secondary Dyslipidemia

Elevated blood cholesterol and triglyceride levels induced by secondary causes are frequently observed. The identification and appropriate handling of these causes are essential for secondary dyslipidemia treatment. Major secondary causes of hypercholesterolemia and hypertriglyceridemia include an unhealthy diet, diseases and metabolic conditions affecting lipid levels, and therapeutic side effects. It is imperative to correct secondary causes prior to initiating conventional lipid-lowering therapy. Guideline-based lipid therapy can then be administered based on the subsequent lipid levels.

Patterns of coronary artery disease trends in patients with nephrotic syndrome: A national inpatient study

BACKGROUND

Individuals with nephrotic syndrome (NS) are thought to have elevated cardiovascular risk because of a known association with hyperlipidemia. Unfortunately, no studies have compared the cardiovascular risk profiles of individual nephrotic syndromes. This study explores the prevalence and patterns of coronary artery disease (CAD) in patients with different types of NS, which may aid in developing risk reduction strategies.

METHODS

This retrospective study queried data from the National Inpatient Sample database spanning 2016-2020 and included patients over the age of 18 years with minimal change disease (MCD), membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS). We analyzed the prevalence and trends of hyperlipidemia and CAD in the study population.

RESULTS

Of the 15,025 cohort, there were 3625 (24.1%) MCD, 4160 (27.7%) MN, and 7315 (48.7%) FSGS. Patients with MN were found to be older with a higher prevalence of hyperlipidemia and CAD compared to other groups. The odds of developing CAD when adjusting for confounding factors were increased in FSGS (adjusted odds [aOR] 1.570, 95% CI 1.406-1.753, p < 0.001) while reduced in MCD (aOR 0.671, 95% CI 0.580-0.777, p < 0.001) and MN (aOR 0.782, 95% CI 0.698-0.876, p < 0.001).

CONCLUSIONS

The divergent results of the different NS types highlight the need for targeted research to better understand and characterize the distinct cardiovascular risk profiles inherent in each type of nephrotic disease for risk stratification.

Endocrine Disorders in Nephrotic Syndrome-A Comprehensive Review

Nephrotic syndrome is a clinical syndrome characterized by massive proteinuria, called nephrotic range proteinuria (over 3.5 g per day in adults or 40 mg/m2 per hour in children), hypoalbuminemia, oncotic edema, and hyperlipidemia, with an increasing incidence over several years. Nephrotic syndrome carries severe morbidity and mortality risk. The main pathophysiological event in nephrotic syndrome is increased glomerular permeability due to immunological, paraneoplastic, genetic, or infective triggers. Because of the marked increase in the glomerular permeability to macromolecules and the associated urinary loss of albumins and hormone-binding proteins, many metabolic and endocrine abnormalities are present. Some of them are well known, such as overt or subclinical hypothyroidism, growth hormone depletion, lack of testosterone, vitamin D, and calcium deficiency. The exact prevalence of these disorders is unknown because of the complexity of the human endocrine system and the differences in their prevalence. This review aims to comprehensively analyze all potential endocrine and hormonal complications of nephrotic syndrome and, vice versa, possible kidney complications of endocrine diseases that might remain unrecognized in everyday clinical practice.

Lipidomic study of kidney in a mouse model with urine flow obstruction

Obstructed urine flow is known to cause structural and functional kidney damage leading to renal fibrosis. However, limited information is available on the change in kidney lipids during urinary tract obstruction. In this study, we investigated the change in lipidome in a mouse model with unilateral ureteral obstruction (UUO). The establishment of the UUO model was confirmed by histopathological examination using transmission electron microscopy. Untargeted liquid chromatography/mass spectrometry was carried out over a time course of 4 and 7 days. Compared to the sham control, the UUO kidney at 7 days showed dilatation of the renal tubule with loss of brush borders and thickening of the capillary endothelium. In the kidney lipidomes obtained from the UUO 7 days group compared to the control, a significant decrease of ceramide, sphingomyelin, phosphatidylcholine, lysophospholipids, and phosphatidylethanolamine was observed, whereas cholesteryl esters, free fatty acids, phosphatidylglycerol, and cardiolipins were significantly increased. The present study revealed the disturbed lipid metabolism in the UUO model, which may provide a clue to potential lipid pathways and therapeutic targets for the early stage of renal fibrosis.

Routine cardiac biomarkers for the prediction of incident major adverse cardiac events in patients with glomerulonephritis: a real-world analysis using a global federated database

RATIONALE & OBJECTIVE

Glomerulonephritis (GN) is a leading cause of chronic kidney disease (CKD). Major adverse cardiovascular events (MACE) are prolific in CKD. The risk of MACE in GN cohorts is multifactorial. We investigated the prognostic significance of routine cardiac biomarkers, Troponin I and N-terminal pro-BNP (NT-proBNP) in predicting MACE within 5 years of GN diagnosis.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Data were obtained from TriNetX, a global federated health research network of electronic health records (EHR).

EXPOSURE OR PREDICTOR

Biomarker thresholds: Troponin I: 18 ng/L, NT-proBNP: 400 pg/mL.

OUTCOMES

Primary outcome: Incidence of major adverse cardiovascular events (MACE).

SECONDARY OUTCOME

was the risk for each individual component of the composite outcome.

ANALYTICAL APPROACH

1:1 propensity score matching using logistic regression. Cox proportional hazard models were used to assess the association of cardiac biomarkers with the primary and secondary outcomes, reported as Hazard Ratio (HR) and 95% confidence intervals (CI). Survival analysis was performed which estimates the probability of an outcome over a 5-year follow-up from the index event.

RESULTS

Following PSM, 34,974 and 18,218 patients were analysed in the Troponin I and NTproBNP cohorts, respectively. In the Troponin I all cause GN cohort, 3,222 (9%) developed composite MACE outcome HR 1.79; (95% CI, 1.70, 1.88, p < 0.0001). In the NTproBNP GN cohort, 1,686 (9%) developed composite MACE outcome HR 1.99; (95% CI, 1.86, 2.14, p < 0.0001).

LIMITATIONS

The data are derived from EHR for administrative purposes; therefore, there is the potential for data errors or missing data.

CONCLUSIONS

In GN, routinely available cardiac biomarkers can predict incident MACE. The results suggest the clinical need for cardiovascular and mortality risk profiling in glomerular disease using a combination of clinical and laboratory variables.

Metabolomic profile of secondary hyperparathyroidism in patients with chronic kidney disease stages 3-5 not receiving dialysis

Introduction

Secondary hyperparathyroidism (SHPT) is a common and serious complication of chronic kidney disease (CKD). Elucidating the metabolic characteristics of SHPT may provide a new theoretical basis for its prevention and treatment. This study aimed to perform a metabolomic analysis of SHPT in patients with CKD stages 3-5 not receiving dialysis.

Methods

A total of 76 patients with CKD, 85 patients with CKD-SHPT, and 67 healthy controls were enrolled in this study. CKD was diagnosed according to the criteria specified in the Kidney Disease Improving Global Outcomes 2012 guidelines. SHPT was diagnosed by experienced clinicians according to the Renal Disease Outcomes Quality Initiative Clinical Practice Guidelines. Serum renal function markers and the lipid profile were analyzed. Untargeted ultra performance liquid chromatography-tandem mass spectrometry was used to analyze the serum metabolites of patients with CKD and SHPT. Multivariate analysis of the data was performed using principal component analysis and partial least square discriminant analysis. Serum differential metabolites were identified and further characterized using databases. Pathway enrichment analysis was performed using the Kyoto Encyclopedia of Genes and Genomes database. Correlations between differential metabolites and clinical parameters were determined using the Spearman correlation.

Results

The serum metabolomic profiles of patients with CKD with and without SHPT differed significantly. Differential metabolites were mainly enriched in the top four Kyoto Encyclopedia of Genes and Genomes pathways: phenylalanine, tyrosine, and tryptophan biosynthesis; sphingolipid metabolism; glycerophospholipid metabolism; and phenylalanine metabolism. In total, 31 differential metabolites were identified; of these, L-tryptophan and (R)-(+)-1-phenylethylamine were decreased, while other amino acids and their derivatives, uremia toxins, carnitine, and lipids, were increased significantly in patients with SHPT compared to those without. The 14 lipid metabolites were positively correlated with levels of Urea, serum creatinine, cystatin C, and triglycerides and negatively correlated with the estimated glomerular filtration rate and levels of total and high- and low-density lipoprotein cholesterol.

Discussion

Disturbed amino acid and lipid metabolism were more apparent in patients with SHPT than in those without. This metabolomic profile of SHPT may provide a therapeutic foundation for its future clinical management.

Longitudinal analysis of blood pressure and lipids in childhood nephrotic syndrome

BACKGROUND

In the current study, longitudinal BP and lipid measurements were examined in a NEPTUNE cohort of children with newly diagnosed nephrotic syndrome (cNEPTUNE). We hypothesized that hypertensive BP and dyslipidemia would persist in children with nephrotic syndrome, regardless of steroid treatment response.

METHODS

A multi-center longitudinal observational analysis of data obtained from children < 19 years of age with new onset nephrotic syndrome enrolled in the Nephrotic Syndrome Study Network (cNEPTUNE) was conducted. BP and lipid data were examined over time stratified by disease activity and steroid exposure. Generalized estimating equation regressions were used to find determinants of hypertensive BP and dyslipidemia.

RESULTS

Among 122 children, the prevalence of hypertensive BP at any visit ranged from 17.4% to 57.4%, while dyslipidemia prevalence ranged from 40.0% to 96.2% over a median of 30 months of follow-up. Hypertensive BP was found in 46.2% (116/251) of study visits during active disease compared with 31.0% (84/271) of visits while in remission. Dyslipidemia was present in 88.2% (120/136) of study visits during active disease and in 66.0% (101/153) while in remission. Neither dyslipidemia nor hypertensive BP were significantly different with/without medication exposure (steroids and/or CNI). In regression analysis, male sex and urine protein:creatinine ratio (UPC) were significant determinants of hypertensive BP over time, while eGFR was found to be a determinant of dyslipidemia over time.

CONCLUSIONS

Results demonstrate persistent hypertensive BPs and unfavorable lipid profiles in the cNEPTUNE cohort regardless of remission status or concurrent steroid or calcineurin inhibitor treatment.

Membranous nephropathy: pathogenesis and treatments

Membranous nephropathy (MN), an autoimmune disease, can manifest at any age and is among the most common causes of nephrotic syndrome in adults. In 80% of cases, the specific etiology of MN remains unknown, while the remaining cases are linked to drug use or underlying conditions like systemic lupus erythematosus, hepatitis B virus, or malignancy. Although about one-third of patients may achieve spontaneous complete or partial remission with conservative management, another third face an elevated risk of disease progression, potentially leading to end-stage renal disease within 10 years. The identification of phospholipase A2 receptor as the primary target antigen in MN has brought about a significant shift in disease management and monitoring. This review explores recent advancements in the pathophysiology of MN, encompassing pathogenesis, clinical presentations, diagnostic criteria, treatment options, and prognosis, with a focus on emerging developments in pathogenesis and therapeutic strategies aimed at halting disease progression. By synthesizing the latest research findings and clinical insights, this review seeks to contribute to the ongoing efforts to enhance our understanding and management of this challenging autoimmune disorder.

The key role of altered tubule cell lipid metabolism in kidney disease development

Kidney epithelial cells have very high energy requirements, which are largely met by fatty acid oxidation. Complex changes in lipid metabolism are observed in patients with kidney disease. Defects in fatty acid oxidation and increased lipid uptake, especially in the context of hyperlipidemia and proteinuria, contribute to this excess lipid build-up and exacerbate kidney disease development. Recent studies have also highlighted the role of increased de novo lipogenesis in kidney fibrosis. The defect in fatty acid oxidation causes energy starvation. Increased lipid uptake, synthesis, and lower fatty acid oxidation can cause toxic lipid build-up, reactive oxygen species generation, and mitochondrial damage. A better understanding of these metabolic processes may open new treatment avenues for kidney diseases by targeting lipid metabolism.

Association of elevated circulating monocyte-platelet aggregates with hypercoagulability in patients with nephrotic syndrome

BACKGROUND

Hypercoagulability emerges as a central pathological feature and clinical complication in nephrotic syndrome. Increased platelet activation and aggregability are closely related to hypercoagulability in nephrotic syndrome. Monocyte-platelet aggregates (MPAs) have been proposed to represent a robust biomarker of platelet activation. The aim of this study was to investigate levels of the circulating MPAs and MPAs with the different monocyte subsets to evaluate the association of MPAs with hypercoagulability in nephrotic syndrome.

METHODS

Thirty-two patients with nephrotic syndrome were enrolled. In addition, thirty-two healthy age and sex matched adult volunteers served as healthy controls. MPAs were identified by CD14 monocytes positive for CD41a platelets. The classical (CD14 + + CD16-, CM), the intermediate (CD14 + + CD16+, IM) and the non-classical (CD14 + CD16++, NCM) monocytes, as well as subset specific MPAs, were measured by flow cytometry.

RESULTS

Patients with nephrotic syndrome showed a higher percentage of circulating MPAs as compared with healthy controls (p < 0.001). The percentages of MPAs with CM, IM, and NCM were higher than those of healthy controls (p = 0.012, p < 0.001 and p < 0.001, respectively). Circulating MPAs showed correlations with hypoalbuminemia (r=-0.85; p < 0.001), hypercholesterolemia (r = 0.54; p < 0.001), fibrinogen (r = 0.70; p < 0.001) and D-dimer (r = 0.37; p = 0.003), but not with hypertriglyceridemia in nephrotic syndrome. The AUC for the prediction of hypercoagulability in nephrotic syndrome using MPAs was 0.79 (95% CI 0.68-0.90, p < 0.001). The sensitivity of MPAs in predicting hypercoagulability was 0.71, and the specificity was 0.78.

CONCLUSION

Increased MPAs were correlated with hypercoagulability in nephrotic syndrome. MPAs may serve as a potential biomarker for thrombophilic or hypercoagulable state and provide novel insight into the mechanisms of anticoagulation in nephrotic syndrome.

Proteomic Analysis of Idiopathic Nephrotic Syndrome Triggered by Primary Podocytopathies in Adults: Regulatory Mechanisms and Diagnostic Implications

Idiopathic nephrotic syndrome (NS) is a heterogeneous group of glomerular disorders which includes two major phenotypes: minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). MCD and FSGS are classic types of primary podocytopathies. We aimed to explore the molecular mechanisms in NS triggered by primary podocytopathies and evaluate diagnostic value of the selected proteomic signatures by analyzing blood proteome profiling. Totally, we recruited 90 participants in two cohorts. The first cohort was analyzed using label-free quantitative (LFQ) proteomics to discover differential expressed proteins and identify enriched biological process in NS which were further studied in relation to clinical markers of kidney injury. The second cohort was analyzed using parallel reaction monitoring-based quantitative proteomics to verify the data of LFQ proteomics and assess the diagnostic performance of the selected proteins using receiver-operating characteristic curve analysis. Several biological processes (such as immune response, cell adhesion, and response to hypoxia) were found to be associated with kidney injury during MCD and FSGS. Moreover, three proteins (CSF1, APOC3, and LDLR) had over 90% sensitivity and specificity in detecting adult NS triggered by primary podocytopathies. The identified biological processes may play a crucial role in MCD and FSGS pathogenesis. The three blood protein markers are promising for diagnosing adult NS triggered by primary podocytopathies.

Cardiovascular risk factors and complications in patients with systemic lupus erythematosus with and without nephritis: a systematic review and meta-analysis

INTRODUCTION

It remains unclear how the presence of renal involvement will affect the cardiovascular (CV) risk factors and complications in patients with SLE.

METHODS

We conducted a systematic review and meta-analysis using PubMed, EMBASE, MEDLINE and Scopus to identify studies published between 1947 and 2022 that evaluate the CV risk factors and complications in patients with SLE with or without lupus nephritis (LN).

RESULTS

58 studies were evaluated, with 22 two-arm studies (n=8675) included in two-arm meta-analysis and 45 studies (n=385 315) included in proportional meta-analysis. Patients with SLE with LN showed significantly higher risk of hypertension (HT) (OR=4.93, 95% CI=3.17 to 7.65, p<0.00001, I2=56%), hyperlipidaemia (OR=11.03, 95% CI=4.20 to 28.95, p<0.00001, I2=0%) and diabetes mellitus (DM) (OR=1.88, 95% CI=1.09 to 3.25, p=0.02, I2=32%) compared with those without LN. Patients with LN showed numerically higher prevalence of myocardial infarction (OR=1.35, 95% CI=0.53 to 3.45, p=0.52, I2=78%) and cerebrovascular accident (OR=1.64, 95% CI=0.79 to 3.39, p=0.27, I2=23%) than general patients with SLE. The incidence rates of CV mortality are also increased in patients with SLE with LN compared with those without LN (11.7/1000 patient-years vs 3.6/1000 patient-years).

CONCLUSION

Patients with SLE with LN show increased risk of CV risk factors including DM, HT and hyperlipidaemia. Early identification and optimal control of these CV risk factors may reduce the risk of CV disease and other non-CV complications.

PROSPERO REGISTRATION NUMBER

CRD42022314682.

Influence of triglyceride concentration in lipoprotein (a) as a function of dyslipidemia

BACKGROUND

Recently, an inverse relationship between the blood concentration of lipoprotein(a) (Lp(a)) and triglycerides (TG) has been demonstrated. The larger the VLDL particle size, the greater the presence of VLDL rich in apoliprotein E and in subjects with the apoE2/E2 genotype, the lower Lp(a) concentration. The mechanism of this inverse association is unknown. The objective of this analysis was to evaluate the Lp(a)-TG association in patients treated at the lipid units included in the registry of the Spanish Society of Atherosclerosis (SEA) by comparing the different dyslipidemias.

PATIENTS AND METHODS

Five thousand two hundred and seventy-five subjects ≥18 years of age registered in the registry before March 31, 2023, with Lp(a) concentration data and complete lipid profile information without treatment were included.

RESULTS

The mean age was 53.0 ± 14.0 years, with 48% women. The 9.5% of subjects (n = 502) had diabetes and the 22.4% (n = 1184) were obese. The median TG level was 130 mg/dL (IQR 88.0-210) and Lp(a) 55.0 nmol/L (IQR 17.9-156). Lp(a) concentration showed a negative association with TG concentration when TG values exceeded 300 mg/dL. Subjects with TG > 1000 mg/dL showed the lowest level of Lp(a), 17.9 nmol/L, and subjects with TG < 300 mg/dL had a mean Lp(a) concentration of 60.1 nmol/L. In subjects without diabetes or obesity, the inverse association of Lp(a)-TG was especially important (p < 0.001). The median Lp(a) was 58.3 nmol/L in those with TG < 300 mg/dL and 22.0 nmol/L if TG > 1000 mg/dL. No association was found between TG and Lp(a) in subjects with diabetes and obesity, nor in subjects with familial hypercholesterolemia. In subjects with multifactorial combined hyperlipemia with TG < 300 mg/dL, Lp(a) was 64.6 nmol/L; in the range of 300-399 mg/dL of TG, Lp(a) decreased to 38. 8 nmol/L, and up to 22.3 nmol/L when TG > 1000 mg/dL.

CONCLUSIONS

Our results show an inverse Lp(a)-TG relationship in TG concentrations > 300 mg/dL in subjects without diabetes, obesity and without familial hypercholesterolemia. Our results suggest that, in those hypertriglyceridemias due to hepatic overproduction of VLDL, the formation of Lp(a) is reduced, unlike those in which the peripheral catabolism of TG-rich lipoproteins is reduced.

Parenting self-efficacy and parenting stress mediates the effects of the association of perceived social support and readiness for discharge among parents of children with primary nephrotic syndrome

PURPOSE

To investigate the level of readiness for discharge among parents of children with primary nephrotic syndrome and to explore the mediating role of parenting self-efficacy and parenting stress between perceived social support and readiness for discharge.

DESIGN AND METHODS

A cross-sectional study was conducted in five large tertiary general hospitals in Hunan, China. Data related to demographics, perceived social support, parenting self-efficacy, parenting stress, and readiness for discharge were collected from 350 parents of children diagnosed with primary nephrotic syndrome. Path analysis was used to determine the mediating roles of parenting self-efficacy and parenting stress in the relationship between perceived social support and readiness for discharge.

RESULTS

Parents of children with nephrotic syndrome in China experienced low perceived social support, low readiness for discharge, and high parenting stress. Factors influencing readiness for discharge include the child's age, duration of illness, first episode or relapse, parental literacy and marital status. Parenting self-efficacy and parenting stress mediated the effects of the association of perceived social support and readiness for discharge.

CONCLUSION

Perceived social support influences the readiness of parents of children with nephrotic syndrome. Parenting self-efficacy and parenting stress have a chain mediating effect of the association of perceived social support and readiness for discharge.

PRACTICE IMPLICATIONS

This study emphasizes the mediating role of the psychological state of the child's parents. Nurses should take steps to increase perceived social support and parenting self-efficacy of the child's parents and to reduce parenting stress in order to improve readiness for discharge.

Membranous nephropathy treatment standard

Membranous nephropathy (MN) is characterized by deposition of immune complexes leading to thickening of glomerular basement membranes. Over time, the understanding of MN has evolved, with the identification of specific autoantibodies against novel podocyte antigens and the unraveling of intricate pathogenic pathways. Although the anti-CD20 monoclonal antibody rituximab is favored as part of the initial therapy in MN, a subgroup of MN patients may be resistant to rituximab necessitating the use of alternative agents such as cytotoxic therapies. In addition, newer agents such as novel anti-CD20 monoclonal antibodies, therapies targeting the CD38-positive plasma cells and anti-complement therapy are being studied in patients who are resistant to traditional treatment strategies. This manuscript furnishes a review of the novel developments in the pathophysiology of MN including the identification of target antigens and current treatment standards for MN, concentrating on evidenced-based interventions designed to attain remission and to prevent disease progression.

Relationship of Thyroid Function with Renal Hemodynamics and Cholesterol Metabolism in Proteinuric Kidney Disease: A Pilot Study

Nephrotic syndrome and hypothyroidism are respectively reported to influence renal hemodynamics and hypercholesterolemia. However, the relationship of proteinuria-associated thyroid function with renal hemodynamics and cholesterol metabolism has yet to be determined in a simultaneous analysis of thyroid, renal, and cholesterol variables. We investigated the hypothesis that the changes in thyroid hormones by proteinuria may contribute to changes in cholesterol metabolism and renal hemodynamics by proteinuria. Twenty-nine patients (17 men and 12 women) with proteinuric kidney disease (mean age 46 years) were enrolled in a pilot study. Data for serum free triiodothyronine (FT3), free thyroxine (FT4), total cholesterol, and filtration fraction (FF; assessed by para-aminohippuric acid clearance) were used in variable-adjusted correlation analyses. The patients had the following data (mean ± standard deviation): urinary protein 5.18 ± 3.28 g/day, FT3 2.18 ± 0.44 pg/mL, FT4 1.03 ± 0.26 ng/dL, FF 0.27 ± 0.07, and total cholesterol 327 ± 127 mg/dL. There was a significant positive correlation of FT3 with FF (β = 0.58, p = 0.01) and a significant inverse correlation of FT4 with total cholesterol (β = -0.40, p = 0.01). A positive correlation of FT3 with FF and an inverse correlation of FT4 with total cholesterol were demonstrated in patients with proteinuric kidney disease. The proteinuria-associated reduction in serum thyroid hormone levels was correlated with hypercholesterolemia and the reduced glomerular FF. Further studies of these relationships are required.

Farnesoid X receptor activation protects against renal fibrosis via modulation of β-catenin signaling

OBJECTIVE

Activation of farnesoid X receptor (FXR), a bile acid nuclear receptor, may be implicated in the pathophysiology of diabetic nephropathy. We explored a possible role for FXR activation in preventing renal fibrosis in high fat diet (HFD)-fed mice.

METHODS

We investigated the effects of HFD on mouse kidney and renal tubular epithelial cells both in vivo and in vitro, and observed the changes of FXR and β-catenin pathway. FXR agonist was also used to alleviate this HFD-induced effect, and the interaction between FXR and β-catenin was further verified.

RESULTS

Mice were fed by a 60% kcal fat diet for 20 weeks developed the typical traits of metabolic syndrome with subsequent renal lipid accumulation and renal injury. Treatment with the FXR agonist CDCA or GW4064 decreased body weight, renal lipid accumulation, as well as renal injury. Moreover, renal β-catenin signaling was activated and improved with FXR-agonist treatment in HFD-fed mice. To examine whether FXR affected β-catenin signaling, and was involved in tubulo-interstitial fibrosis, we explored the FXR expression and function in ox-LDL induced-renal tubular injury. In rat proximal tubular epithelial cells (NRK-52E) stimulated by ox-LDL, FXR protein was decreased compared to control group, and phosphorylated (Ser675) β-catenin was activated by ox-LDL in a dose- and time-dependent manner. Ox-LDL enhanced α-SMA and fibronectin expressions and reduced E-cadherin levels, whereas FXR agonism or FXR overexpression inhibited fibronectin and α-SMA expressions and restored E-cadherin. Moreover, FXR agonist treatment also decreased phosphorylated (Ser675) β-catenin, nuclear translocation and β-catenin-mediated transcription induced by ox-LDL in NRK-52E cells. We showed that FXR could bind with β-catenin via the AF1 domain, and disrupt the assembly of the core β-catenin/TCF4 complex.

CONCLUSION

These experimental data suggest that FXR activation, via modulating β-catenin signaling, may contribute to attenuating the development of lipid-mediated tubulo-interstitial fibrosis.

High-salt diet induces dyslipidemia through the SREBP2/PCSK9 pathway in dahl salt-sensitive rats

A high-salt diet is known to increase serum cholesterol levels; however, the underlying mechanism of salt-induced dyslipidemia in patients with salt-sensitivity remains poorly understood. We aimed to investigate whether high-salt diet (HSD) can induce dyslipidemia and elucidate the underlying mechanism of salt-induced dyslipidemia in Dahl salt-sensitive (SS) rats. Metabolomic and biochemical analyses revealed that the consumption of an HSD (8 % NaCl) significantly increased the serum levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in SS rats. The enzyme-linked immunosorbent assay demonstrated an increase in circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) levels, accompanied by a decrease in hepatic low-density lipoprotein receptor (LDLR) levels due to HSD consumption. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis revealed that HSD consumption activated sterol regulatory element-binding protein-2 (SREBP2) expression in the liver and kidney, resulting in upregulation of PCSK9 at the transcriptional level in the liver and at the translational level in the kidney, ultimately increasing circulating PCSK9 levels. The combined effects of HSD on the liver and kidney contributed to the development of hypercholesterolemia. Furthermore, an in vitro assay confirmed that high-salt exposure led to an increase in the protein expression of SREBP2 and PCSK9 secretion, thereby reducing low-density lipoprotein (LDL) uptake. This study, for the first time, shows that an HSD induces dyslipidemia through activation of the SREBP2/PCSK9 pathway, providing new insights into the prevention and treatment of dyslipidemia in patients with salt sensitivity.

Association of Fibroblast Growth Factor 23 with Blood Pressure in Primary Proteinuric Glomerulopathies

INTRODUCTION

Fibroblast growth factor 23 (FGF23) has direct effects on the vasculature and myocardium, and high levels of FGF23 are a risk factor for cardiovascular disease (CVD); however, the impact of FGF23 on CVD in primary proteinuric glomerulopathies has not been addressed.

METHODS

The associations of baseline plasma intact FGF23 levels with resting blood pressure (BP) and lipids over time among adults and children with proteinuric glomerulopathies enrolled in the Nephrotic Syndrome Study Network (NEPTUNE) were analyzed using generalized estimating equation regression analyses. Models were adjusted for age, sex, glomerular diagnosis, follow-up time, estimated glomerular filtration rate, urine protein/creatinine ratio, obesity, and serum phosphorous levels.

RESULTS

Two hundred and four adults with median FGF23 77.5 (IQR 51.3-119.3) pg/mL and 93 children with median FGF23 62.3 (IQR 44.6-83.6) pg/mL were followed for a median of 42 (IQR 20.5-54) months. In adjusted models, each 1 µg/mL increase in FGF23 was associated with a 0.3 increase in systolic BP index at follow-up (p < 0.001). Greater baseline FGF23 was associated with greater odds of hypertensive BP (OR = 1.0003; 95% CI 1.001-1.006, p = 0.03) over time. Compared to tertile 1, tertile 2 (OR = 2.1; 95% CI 1.12-3.99, p = 0.02), and tertile 3 (OR = 3; 95% CI 1.08-8.08, p = 0.04), FGF23 levels were associated with greater odds of hypertensive BP over time. Tertile 2 was associated with greater triglycerides compared to tertile 1 (OR = 48.1; 95% CI 4.4-91.9, p = 0.03).

CONCLUSION

Overall, higher baseline FGF23 was significantly associated with hypertensive BP over time in individuals with proteinuric glomerulopathies. Further study of FGF23 as a therapeutic target for reducing CVD in proteinuric glomerular disease is warranted.

A Counterion-Free Strategy for Chronic Metabolic Acidosis Based on an Orally Administered Gut-Restricted Inorganic Adsorbent

Chronic metabolic acidosis, arising as a complication of chronic kidney disease (CKD), not only reduces patients' quality of life but also aggravates renal impairment. The only available therapeutic modality, involving intravenous infusion of NaHCO3 , engenders undesirable sodium retention, thereby increasing hemodynamic load and seriously exacerbating the primary disease. This deleterious cascade extends to the development of cardiovascular diseases. Herein, an orally administered, gut-restricted inorganic adsorbent that can effectively alleviate chronic metabolic acidosis without causing any electrolytic derangement or superfluous cardiovascular strain is developed. The genesis of ABC-350 entails the engineering of bismuth subcarbonate via annealing, thereby yielding a partially β-Bi2 O3 -doped (BiO)2 CO3 biphasic crystalline structure framework enriched with atomic vacancies. ABC-350 can selectively remove chloride ions and protons from the gastrointestinal tract, mimicking the physiological response to gastric acid removal and resulting in increased serum bicarbonate. Owing to its gut-restricted nature, ABC-350 exhibits commendable biosafety, averting undue systemic exposure. In two rat models of metabolic acidosis, ABC-350 emerges not only as a potent mitigator of acidosis but also effects discernible amelioration concerning proximal tubular morphology, interstitial fibrosis, and the incendiary cascades incited by metabolic acidosis. ABC-350, as the translationally relevant material, provides a promising strategy for the treatment of metabolic acidosis.

Tripterygium glycosides improve abnormal lipid deposition in nephrotic syndrome rat models

OBJECTIVE

The purpose of this study was to determine the effect of tripterygium glycosides (TGs) on regulating abnormal lipid deposition in nephrotic syndrome (NS) rats.

METHODS

Sprague-Dawley (SD) rats were injected with 6 mg/kg doxorubicin to construct nephrotic syndrome models (n = 6 per group), and then administered with TGs (10 mg/kg·d^-1), prednisone (6.3 mg/kg·d^-1), or pure water for 5 weeks. Biomedical indexes, such as urine protein/creatinine ratio (PCR), blood urea nitrogen (BUN), serum creatinine (Scr), serum albumin (SA), triglycerides (TG), total cholesterol (TC)were investigated to evaluate the renal injury of rats. H&E staining experiment was used to assess the pathological alterations. Oil Red O staining was used to assess the level of renal lipid deposition. Malondialdehyde (MDA) and glutathione (GSH) were measured to assess the extent of oxidative damage to the kidney. TUNEL staining was used to assess the status of apoptosis in the kidney. Western blot analysis was performed to examine the levels of relevant intracellular signaling molecules.

RESULTS

After treatment with TGs, those tested biomedical indexes were significantly improved, and the extent of kidney tissue pathological changes and lipid deposition in the kidney was diminished. Treatment with TGs decreased renal oxidative damage and apoptosis. Regarding the molecular mechanism, TGs significantly increased the protein expression levels of Bcl-2 but decreased the levels of CD36, ADFP, Bax, and Cleaved caspase-3.

CONCLUSION

TGs alleviates renal injury and lipid deposition induced by doxorubicin, suggesting that it may be a new strategy for reducing renal lipotoxicity in NS.

An integrated bioinformatics approach to identify key biomarkers in the tubulointerstitium of patients with focal segmental glomerulosclerosis and construction of mRNA-miRNA-lncRNA/circRNA networks

OBJECTIVE

The purpose of this study was to identify potential biomarkers in the tubulointerstitium of focal segmental glomerulosclerosis (FSGS) and comprehensively analyze its mRNA-miRNA-lncRNA/circRNA network.

METHODS

The expression data (GSE108112 and GSE200818) were downloaded from the Gene Expression Omnibus database (https://www.ncbi.nlm.nih.gov/geo/). Identification and enrichment analysis of differentially expressed genes (DEGs) were performed. the PPI networks of the DEGs were constructed and classified using the Cytoscape molecular complex detection (MCODE) plugin. Weighted gene coexpression network analysis (WGCNA) was used to identify critical gene modules. Least absolute shrinkage and selection operator regression analysis were used to screen for key biomarkers of the tubulointerstitium in FSGS, and the receiver operating characteristic curve was used to determine their diagnostic accuracy. The screening results were verified by quantitative real-time-PCR (qRT-PCR) and Western blot. The transcription factors (TFs) affecting the hub genes were identified by Cytoscape iRegulon. The mRNA-miRNA-lncRNA/circRNA network for identifying potential biomarkers was based on the starBase database.

RESULTS

A total of 535 DEGs were identified. MCODE obtained eight modules. The green module of WGCNA had the greatest association with the tubulointerstitium in FSGS. PPARG coactivator 1 alpha (PPARGC1A) was screened as a potential tubulointerstitial biomarker for FSGS and verified by qRT-PCR and Western blot. The TFs FOXO4 and FOXO1 had a regulatory effect on PPARGC1A. The ceRNA network yielded 17 miRNAs, 32 lncRNAs, and 50 circRNAs.

CONCLUSIONS

PPARGC1A may be a potential biomarker in the tubulointerstitium of FSGS. The ceRNA network contributes to the comprehensive elucidation of the mechanisms of tubulointerstitial lesions in FSGS.

Loss-of-Function Homozygous Variant in LPL Causes Type I Hyperlipoproteinemia and Renal Lipidosis

Introduction

Lipoprotein lipase (LPL) is an important enzyme in lipid metabolism, individuals with LPL gene variants could present type I hyperlipoproteinemia, lipemia retinalis, hepatosplenomegaly, and pancreatitis. To date, there are no reports of renal lipidosis induced by type I hyperlipoproteinemia due to LPL mutation.

Methods

Renal biopsy was conducted to confirm the etiological factor of nephrotic syndrome in a 44-year-old Chinese man. Lipoprotein electrophoresis, apoE genotype detection, and whole-exome sequencing were performed to confirm the dyslipidemia type and genetic factor. Analysis of the 3-dimensional protein structure and in vitro functional study were conducted to verify variant pathogenicity.

Results

Renal biopsy revealed numerous CD68 positive foam cells infiltrated in the glomeruli; immunoglobulin and complement staining were negative; and electron microscopy revealed numerous lipid droplets and cholesterol clefts in the cytoplasm of foam cells. Lipoprotein electrophoresis revealed that the patient fulfilled the diagnostic criteria of type I hyperlipoproteinemia. The apoE genotype of the patient was the ε3/ε3 genotype. Whole-exome sequencing revealed an LPL (c.292G > A, p.A98T) homozygous variant with α-helix instability and reduced post-heparin LPL activity but normal lipid uptake capability compared to the wild-type variant.

Conclusion

LPL (c.292G > A, p.A98T) is a pathogenic variant that causes renal lipidosis associated with type I hyperlipoproteinemia. This study provides adequate evidence of the causal relationship between dyslipidemia and renal lesions. However, further research is needed to better understand the pathogenetic mechanism of LPL variant-related renal lesions.

A Study of Dyslipidemia and Its Clinical Implications in Childhood Nephrotic Syndrome

BACKGROUND

Nephrotic syndrome in children is characterized by dyslipidemia, which is an indirect risk factor for cardiovascular diseases, progressive glomerulosclerosis, and related complications. The objective is to determine the range of lipid profile abnormalities in relation to onset, relapse, and remission, as well as to determine if there is any relationship between dyslipidemia and the frequency of relapses.

METHODS

One hundred and two diagnosed cases of nephrotic syndrome in the age group of less than 12 years were included, out of which 64 patients belonged to the first episode of nephrotic syndrome and 38 patients were relapse cases. Steroid-resistant nephrotic syndrome cases or patients with a history of diabetes mellitus, hypothyroidism, familial hypercholesterolemia, children with chronic kidney disease, and edema due to other causes were excluded from the study.

RESULTS

There was a statistically significant increase in lipid parameters except for high-density lipoprotein (HDL) cholesterol at the disease onset when compared to remission in cases of the first episode as well as relapse cases of nephrotic syndrome. There was a positive correlation between relapse frequency and dyslipidemia. Dyslipidaemia was also associated with low serum albumin, with a p-value <0.001, which is statistically significant.

CONCLUSION

Dyslipidemia is significantly higher in relapse cases of nephrotic syndrome and remains higher even during remission. Dyslipidemia is a directly associated risk factor for atherosclerosis and coronary heart disease (CAD), along with progressive glomerulosclerosis. Early identification and treatment of hyperlipidemia is therefore justified so that along with longevity, we can also improve the quality of life of children suffering from nephrotic syndrome.